Single-molecule studies of RNA virus replication
Dr Nicole Robb, Associate Professor, Biomedical Sciences Directorate

Abstract: RNA viruses are a major cause of morbidity and mortality in both humans and animals, and result in a significant health and economic burden worldwide. Our group uses a range of single-molecule microscopy techniques to study RNA virus replication, their morphology, and to develop novel methods for their diagnosis. In this talk I’ll describe our work using single-molecule FRET, a molecular ruler used to measure inter-protein and RNA-RNA interactions, to study influenza and SARS-CoV-2 replication complexes, and how these assays can be used to provide information on replication dynamics and the mechanism of antiviral inhibitors.

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Interlocking nanomechanics of kinesin and microtubules
Professor Robert Cross, Biomedical Sciences Directorate

Abstract: Kinesins are microtubule-based cargo transporters whose activities are central to the self-organisation of eukaryotic cells and organisms. The archetype of the kinesin superfamily is kinesin-1. Kinesin-1 motors haul cargo towards the plus ends of microtubules, using a walking action in which the twin heads of each molecule interact alternately with the microtubule.

We are interested in this stepping mechanism, and in that of other members of the kinesin family of molecular motors, which is ancient and highly diverse. We have so far tended to concentrate mostly on the problem of how kinesins work as molecular machines, attacking this problem using protein engineering and single molecule optical trapping. More recently, we have realized that there is appreciable crosstalk between kinesin and tubulin, the building block for microtubules. Not only kinesin, but also a number microtubule-associated proteins (MAPS) and a number of drugs, including crucially-important cancer drugs like taxol, can change the structure of microtubules - and changes to the structure of microtubules can, as we now realize, feed back to determine the speed, power and directionality of kinesin stepping.

I will present results from some of our newest experiments, designed to explore how structural switching of microtubules feeds back on kinesin stepping, and vice versa.